chapters/13.markdown @ 436f8ce22479

Buffer-Local Abbreviations
==========================

That last chapter was a monster, so let's tackle something easier.  We've seen
how to define buffer-local mappings and options, so let's apply the same idea to
abbreviations.

Open your `foo` and `bar` files again, switch to `foo`, and run the following
command:

    :::vim
    :iabbrev <buffer> --- &mdash;

While still in `foo` enter insert mode and type the following text:

    :::text
    Hello --- world.

Vim will replace the `---` for you.  Now switch to `bar` and try it.  It should
be no surprise that it's not replaced, because we defined the abbreviation to be
local to the `foo` buffer.

Autocommands and Abbreviations
------------------------------

Let's pair up these buffer-local abbreviations with autocommands to set them to
make ourselves a little "snippet" system.

Run the following commands:

    :::vim
    :autocmd FileType python     :iabbrev <buffer> iff if:<left>
    :autocmd FileType javascript :iabbrev <buffer> iff if ()<left>

Open a Javascript file and try out the `iff` abbreviation.  Then open a Python
file and try it there too.  Vim will perform the appropriate abbreviation
depending on the type of the current file.

Exercises
---------

Create a few more "snippet" abbreviations for some of the things you type often
in specific kinds of files.  Some good candidates are `return` for most
languages, `function` for javascript, and things like `&ldquo;` and `&rdquo;`
for HTML files.

Add these snippets to your `~/.vimrc` file.

Remember: the best way to learn to use these new snippets is to *disable* the
old way of doing things.  Running `:iabbrev <buffer> return NOPENOPENOPE` will
*force* you to use your abbreviation instead.  Add these "training" snippets to
match all the ones you created to save time.